Grid-connected Inverter Model and Control Strategies for Photovoltaic Application

This paper describes the three-phase grid-connected inverter model for photovoltaic application. The inverter system model and control strategies are carried in MATLAB/SIMULINK environment. Utilizing both proportional-integral controllers for the control loops, and the sinusoidal pulse-width modulation switching signals generation technique for the IGBTs, the inverter control system capable of converting dc power from PV to power up the ac load. Not only stabilize the output voltage and current, the inverter also feeds the excess PV power to the utility grid. The system is simulated with the PV simulator which facilitates the PV power to be fed to the inverter input stage. The control system produced 2.48% and 4.64% of output voltage and current total harmonic distortion, respectively. The simulation results such as the ac output voltages and currents, system power flow, and grid disturbances detection signals, proved the effectiveness of the developed control algorithm.